US2844348A - Adjustable support - Google Patents

Description

July 22, 1958 -r. H. JORDAN ADJUSTABLE SUPPORT Filed Nov 8, 1955 T IjOMAS H. JORDAN Am! ATT'YS collapse.

United States Patent .9

ADJUSTABLE SUPPORT Thomas Hr Jordan, Chicago, Ill.

Application November 8, 1955, SerialNo. 545,658

2 Claims. (CL 248-354) This invention relates to supports or .jacks and more particularly, to an adjustable support or jack which may be manually extended to a distance approximating the distance between the object .to .be supportedor lifted and the ground and then adjusted to tighten. the support in position or lift the object if a jack isrequired.

Adjustable jacks of .this type. are. particularly advantageous in cases where the distance between. the. object and the ground is comparatively great and. the distance that the object is to be lifted is relatively small, Such a jack would be particularly advantageous in railroad or highwayv accidents where it is imperative that. heavy objects be lifted with great speed such as, for instance, to free entrapped passengers. A device of this type would be especially suitable, also, as a stilt-leg support. member used to provide a counter-supportfor vehicles carrying mobile cranes. .In both. of these. suggested uses the fact that the support or jackrnay be quickly and conveniently brought into operative position is of prime importance. A disadvantage,.however, of priorart adjustable supports or jacks is .that they are unable to. carry safely varying heavy loads such as. those encountered. in balancing a mobile crane or lifting .a heavy vehicle: such as a locomofive or the like, where shifting. ofthe load may cause slipping of the adjusted support sections. These devices are commonly constructed with an extensible. section .that'can be secured at any of several points along a piston. or plunger that, in turn, .is movable through alimited distance by means of a device giving mechanical advantage,

such as a screw or the like. 'Themeansernployedin these devices for securing the extensible. member to the piston or plunger at various positions therealong, are inadequate because the entire load is supported at one or two; points by each member of relatively small .size.. In addition, these devices are unsafe in operation because no effective means has been providedto lock the extensible member to the piston or plunger positively to prevent inadvertent Furthermore, the known-typeset snpports or jacks are extremely cumbersome. .to operate, both in placing inposition for use and in removing when they were no longer needed. Y

With this in mind, a primary object of the present in: vention is to provide an adjustable support or. jack. by means of which relatively great loads may be supported orlifted safely and rapidly.

A further object of the invention is to provide an ad'- j'ustable support or jack. of this type in which load, at all times, is distributed over a maximum bearing area between the telescopingly adjustable parts of the device.

IAnother object of the invention is to provide a support or jack of the stated type wherein the extensible member is positively locked to the piston or plunger so that the. possibility of inadvertent disconnection of these elements is obviated.

; A further object of the invention is to provide an adjustable support or jack that may be conveniently and 2,844,348 Patented July 22, 1958 easily placed in, position and adjusted for use and. just as easily removed.

Other and further objects, advantages and features of the present invention will be apparent to those skilled in the art from the following description of a specific. embodiment of the invention, taken in conjunction with the accompanying drawings. in which similar reference characters relate to similar parts and in which:

Fig. 1 is an elevational view, partly in section, of a support or jack made in accordance with the present invention;

Fig. 2. is a view similar to Fig, l but showing the sup port. or jack in extended position and with. the latching elements opened;

Fig. 3 is a sectional plan view of the same taken substantially on line .3.3 of Fig. .2; and

Fig. 4. is a fragmentary view in elevation, as taken on line 44 of Fig. 1, showing the relation of the locking elements in locked position. I

Referring now to the drawings and more particularly to Fig- 1, the support or jack of the. present invention comprises essentially a piston or plunger solid in form and cylindricalin configuration and having at its lower end .a threaded. bore 12 for reception of a jack screw 14 which is suitably mounted by means of a ball joint 16 to a sole plate 18. The sole plate 18 may be of a size cornmensurate with the load to be distributed on the ground or other base supporting surface- The ball joint 16 per? mi-ts .efiective use of the support or jack at an angle. to the vertical. Thus, in supporting a mobile crane, a plu-. ralit-y of the supports maybe disposed about the vehicle either vertically or at difierent angles, to prevent tipping of the vehicle in whatever position the crane. may assume. Mounted in surrounding relation'to the piston or plunger 10 is an extensible. tube 2 0 which may be slid along the plunger 10 to a. position, approximating the distance between the load to be supported or lifted and the ground and secured in this position.

According .to the present invention, improved means are provided for assuring a positive connection between the piston 1.0 and the. extensible tube 2.0 so that the entire load imparted to. the tube 20 will be transmitted and dis-. tributed uniformly to the plunger 10 and thus to. the ground. To this. end, a pair of longitudinally extending diametrically opposed levers 22 are pivotally mounted by hearing pins,23 in respective pairs .of radially-extending ears 24, which are secured as by welding or the. like to the outer surface of the tube 26 approximately midway between its. ends, the lower extremity of each of the levers 22 beingv provided with inwardly-extending foot member 2.6 to the inner end of which is secured a locking shoe 28. which is generally semi circular in shape as shown in Fig. 3. The two lockingshces 2.8. are relatively thick and wide and cooperate each with the other to form a heavy split ring. These shoes 28 are selectively received in longitudinally spaced annular channels. 3.0 formed in the periphery cfthe. piston or plunger 19. Preferably, the apertures in the ears 2%, through which the bearing pins 23 ex-. tend, are slightly elongate transversely of the bearing pin axis to permit the shoes 2.8.10 swing freely below the. end of the tube 2.0., when the support device is unloaded, and to permit the arms 22 to shift, upwardly so. that the end of the tube will engage. the shoes when a load is applied.

The channels 30 are dimensioned to correspond generallywith the configuration of the shoes .28 and are defined, in part, by annular shoulders .31. The channels 30 are spaced apart a greater distance than their width longitudinally of the plunger 10 and the shoes 28 are of sufiicient'width that when they are inoperative seated pm sition in one of the grooves 30, the lower edge of the tube 20 is supported by the split ring formed by the shoes 28 substantially throughout its circumference. The inner marginal edges of the shoes 28 rest on one of the s'honl ders 31. By this arrangement, the full shear strength of the thickness of the shoes directly resists the load forces tending to urge the plunger into the tube and the entire load supported or lifted is transmitted from the tube 20 directly and evenly to substantially the entire area of the engaged shoulder of the plunger 10.

Referring again to Figs. 1 and 2, the levers 22 are normally urged into operative position by means of compression springs 32 which are suitably arranged between the upper extremities of the levers 24 and the tube 20. In addition, positive interlocking means are provided to retain the shoes 28 in seated position in the channels 3t}. To this end, a locking sleeve 34 is s'lidably arranged in telescoping relation on the tube 29 and the sleeve 34 is provided at its lower edge with diametrically opposed slots 36 corresponding generally to the conformation of the foot sections 26. tioned within one of the grooves 30, and the sleeve 34 is lowered from the position shown in Fig. 2 to that shown in Fig. l, the lower marginal edges of the sleeve 34 straddle the foot sections 26, which enter the slots 36, and the periphery of the split ring formed by shoes 28 is completely enclosed "by these edges, as indicated in Fig. 4, so that inadvertent displacement of the shoes is positively prevented. Referring now to Fig. 3, it will also be seen that the particular shape of the locking ring formed by the shoes 28, with respect to the annular shoulders 31, is such that probability of accidental displacement before the sleeve 34 is moved into locking position is minimized. For instance, the confronting edges of the shoes 28 must travel a distance substantially equal to the entire width of the shoes before the shoes clear the shoulder 31. The shoes are desirably of suflicient thickness that the load may be borne by these edges in event of some inadvertent slippage during initial adjustment of the device to load carrying position.

The support or jack of my invention may be dismantled quickly and efficiently with but one motion by the operator. For this purpose, a pair of oppositely disposed cam lobes 38 is mounted on the exterior surface of the sleeve 34 for cooperation with a corresponding pair of cam lo'bes 40 on the inner surfaces of the levers 22 to effect automatic release or withdrawal of the shoes 28 from the grooves 30 whenever the sleeve 34 is raised, to the unlocked position shown in Fig. 2. Thus, by the operation of lifting the sleeve 34 by its handle 42 to releasing position the cams 38 are caused to engage the cams 40 and swing the arms 22 outwardly to withdraw the shoes 28 from engagement with the plunger 10.

The device of my invention is normally stored with the plunger 10 received entirely within the tube 20. As shown in Fig. 1, the unit is locked in this position by the shoes 28 which are urged by the springs 32 to the position beneath the plunger 10 shown in this figure. When using the improved device, the sleeve 34 is grasped by the handle 42 and is moved upwardly so that the cam lobes 38 on the sleeve 34 engage the cam lobes 40 on the levers 22 and swing these levers outwardly to disengage the shoes 28 so that the tube 20 may be extended relative to the plunger 10 to a position approximating the distance between the load and the ground. The sleeve 34 is then retracted to release the arms 22 so that the shoes 28 will automatically drop into the closest groove- 30 when the tube 20 and plunger 10 are appropriately adjusted. The sleeve 34 is then moved downwardly to its locking position so that its lower end slots 36 receive the foot sections 26 and the body of the sleeve surrounds the periphery of the split ring formed by the shoes 28. The weight of the sleeve 34, of course, retains it in this locking position. The screw 14 may then be turned by means of a radial operating bar 44 to effect lifting of the plunger 10 and the tube 20.

Thus, when the shoes 28 are posi- When the improved device is used as a support for a mobile crane or the like, the screw 14 is utilized mainly to obtain a full or final adjustment where the device will sustain the intended load. In dismantling the support or jack, the sleeve 34 is moved upwardly by means of the handle 42, so that the cam lobes 38 engage the cam lobes 40 and cause outward pivotal movement of the levers 22 to withdraw the shoes 28. By this arrangement, both the locking shoes 28 and the interlocking sleeve 34 are disengaged with one motion by the operator.

In the form shown, the improved device is provided with a tongue 45 extending upwardly from the top surface of an end cap 46 on tube 20. This tongue 45 may be used in conjunction with a yoke permanently mounted on the chassis of a mobile crane, or on an extensible and retractible outrigger forming a part of the mobile crane chassis, for attaching the device to the vehicle. When used as a jack, of course, this tongue element may be omitted and the end cap 46 will 'function as the upper load bearing member.

It will be apparent that this invention may be embodied in devices which difier in many respects and details from the particular embodiment disclosed, and many modifications which do not go beyond the scope of the invention will readily suggest themselves to those skilled in the art. It is, therefore, not intended that the invention be limited to the exact construction shown and described, but only to the inventive concept as defined in the appended claims.

I claim:

1. A supporting apparatus comprising a tube having an open end, a cylindrical plunger telescopically arranged within said tube and extensible from the open end thereof, said plunger having a plurality of longitudinally spaced peripheral grooves defined by annular axially facing shoulders, means mounted on said tube for transmitting loads from said tube to said plunger substantially throughout the area of a selected shoulder, said means comprising a pair of longitudinally extending levers pivotally mounted on opposite sides of said tube and extending to the open end thereof, a foot section on each of said levers projecting toward said plunger, a semi-circular locking shoe on each of said foot sections opening toward said plunger, said locking shoes being in a common plane and together forming a split ring selectively engageable in said grooves to rest on the respective one of said shoulders, said shoes being of a width to engage the open end of said tube when seated in one of said grooves, means on said levers to allow limited movement of said foot sec- 'tions axially of said tube and cause said shoes to bear against the end of the tube when under load, and means for locking said shoes in said grooves comprising a sleeve slidably mounted on said tube and having diametrically opposed end slots for receiving said foot sections whereby the lower marginal edges of said sleeve will overlap and envelop the outer periphery of said shoes, said sleeve being slida'ble along said tube to release said shoes.

2. A supporting apparatus comprising a tube having an open end, 'a plunger telescopically arranged within said tube, said plunger having a plurality of longitudinally spaced peripheral grooves defined by axially facing shoulders, means mounted on said tube for transmitting loads therefrom to said plunger comprising a pair of longitudinally extending levers pivotally mounted on said tube and extending to the open end thereof, a foot section on each of said levers projecting toward said plunger, a locking shoe on each of said foot sections, said locking shoes being in a common plane and selectively receivable in said grooves to rest on one of said shoulders, said shoes being of a width to overlap and engage the open end edge of said tube when seated in one of said grooves, means for locking said shoes in said grooves comprising a sleeve slidab'ly mounted on said tube for axial movement therealong and having diametrically opposed end slots for receiving said foot sections whereby the end margin of said sleeve will envelop the outer periphery of said shoes when the sleeve is moved to the open end of said tube, and means for disengaging said shoes from said grooves comprising a pair of cam lobes mounted on said sleeve each in the plane of a respective lever and a corresponding cam lobe mounted on the inner sunface of each of said levers between the pivots thereof and the open end of said tube, whereby upon movement of said sleeve away from the open end of said tube the said shoes are uncovered and the sleeve cams engage said lever cams to swing said levers outwardly.

References Cited in the file of this patent UNITED STATES PATENTS Bueke Oct. 20, Hatch Mar. 18, Biedermann Mar. 30, Baldauf Feb. 12, We1ker July 21, Schrei'ber July 4,

FOREIGN PATENTS Switzerland Jan. 2, Germany July 22,

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